DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   Ground level deck design (http://www.diychatroom.com/f19/ground-level-deck-design-139755/)

anesthes 04-09-2012 09:03 AM

Ground level deck design
 
1 Attachment(s)
Does this look ok to you?

It will have a ledger bolted to the house, but I want a 24" cantilever to the garage (not bolted to the garage). Probably bring it within a few inches of the garage, just close enough to be able to walk into the garage door. Going to attempt to make the deck the same height as the garage door threshold.

-- Joe

cortell 04-09-2012 09:44 AM

That looks good to me. The 24" cantilever is well within the 3:1 rule of thumb, as long as you don't have a joint over the sonotubes closest to the garage. The joist span looks good, too. The only thing not detailed is the sonotubes spacing (along the beam). The only numbers I have memorized is that two 2x8s beams supporting 10' joist spans must have supports than span no more than 6.1'. If you're anywhere close to that, given you're using three 2X10's, you're good.

anesthes 04-09-2012 09:53 AM

Quote:

Originally Posted by cortell (Post 894991)
That looks good to me. The 24" cantilever is well within the 3:1 rule of thumb, as long as you don't have a joint over the sonotubes closest to the garage. The joist span looks good, too. The only thing not detailed is the sonotubes spacing (along the beam). The only numbers I have memorized is that two 2x8s beams supporting 10' joist spans must have supports than span no more than 6.1'. If you're anywhere close to that, given you're using three 2X10's, you're good.

Thanks.

I'll just use 20' lengths of PT so no joints.

If there is a variation in the level of the sonotubes for whatever reason, do you just shim the beam level?

-- Joe

cortell 04-09-2012 10:01 AM

Quote:

Originally Posted by anesthes (Post 894996)
Thanks.
If there is a variation in the level of the sonotubes for whatever reason, do you just shim the beam level?
-- Joe

Assuming the variation is not significant, I'd use hot-dipped galvanized or stainless steel shims (the latter if you're a big spender).

joecaption 04-09-2012 11:46 AM

Why not make it all free standing? Then there's 0 chance of siding and wall damage.
Also that deck needs to be below the threshold or spaced out away from it or the water will get in under the threshold. Look around on some of the older post on here and see all the people having to deal with subfloor, bottom plate, sheetrock damage, all caused by the deck, stoop, porch being level with the threshold.

anesthes 04-09-2012 11:51 AM

Quote:

Originally Posted by joecaption (Post 895045)
Why not make it all free standing? Then there's 0 chance of siding and wall damage.
Also that deck needs to be below the threshold or spaced out away from it or the water will get in under the threshold. Look around on some of the older post on here and see all the people having to deal with subfloor, bottom plate, sheetrock damage, all caused by the deck, stoop, porch being level with the threshold.

Hi,

Level with the threashold but not touching it. I tried to illustrate in my bad picture the deck stopping just short of the garage because I did not want it in contact with it.

The deck on the house side is bolted to the foundation, a number of inches (8 or so) from the bottom of the siding so there is no risk of rotting the rim joist or sill.

The garage is lower in elevation than the house , and right now soils are backfilled against it causing water infiltration. I'm going to excavate and re-grade the entire area, place the sonotubes with big foots min 48" down.

The plan is to divert water away from the garage and house, and offer a platform to walk from the house to the garage without standing in mud :)

-- Joe

cortell 04-09-2012 12:06 PM

Nice. It sounds like you've done your research. Big foots and sonotubes 48" down. Your profile doesn't mention a location, but that's going to be below frost line in most of the contiguous US. You're over engineering the joists, the beams...sounds to me like that deck is going to be around longer than any of us ;-) Mike Holmes would probably give you a big bear hug.

anesthes 04-09-2012 12:31 PM

Quote:

Originally Posted by cortell (Post 895064)
Nice. It sounds like you've done your research. Big foots and sonotubes 48" down. Your profile doesn't mention a location, but that's going to be below frost line in most of the contiguous US. You're over engineering the joists, the beams...sounds to me like that deck is going to be around longer than any of us ;-) Mike Holmes would probably give you a big bear hug.

Hi,

Thank you!. I'm in New Hampshire and we have a 50psf snow load for decks, and I like keeping inspectors happy.

I just hope the height works out. The other thing I'm a little nervous about is anchoring the ledger to the block foundation. It's code acceptable with the appropriate anchors, but my experience is that blocks like to crumble.

This deck will be slightly above ground level, and well below 30". When is a 'step' required, like what is the max rise from ground level to the deck? Is it the same as a stair tread ? Since the 2x10 + beam + decking would be greater than that, I guess the best bet would be to make a continuous step on the sides, unless I wanted a specific stair location + railings ?

-- Joe

cortell 04-09-2012 12:49 PM

Quote:

Originally Posted by anesthes (Post 895081)
Hi,
I just hope the height works out. The other thing I'm a little nervous about is anchoring the ledger to the block foundation. It's code acceptable with the appropriate anchors, but my experience is that blocks like to crumble.

I'd be particularly nervous about it if it's cinder block (ash composition). You'll know its concrete block if you can see bits of gravel. Also, you might get extremely lucky and your target row of blocks is a bond beam. Those blocks would have concrete or mortar in them. If it's the top one or two rows of blocks, there's actually a decent chance it is.

Quote:

Originally Posted by anesthes (Post 895081)
This deck will be slightly above ground level, and well below 30". When is a 'step' required, like what is the max rise from ground level to the deck? Is it the same as a stair tread ? Since the 2x10 + beam + decking would be greater than that, I guess the best bet would be to make a continuous step on the sides, unless I wanted a specific stair location + railings ?

I'd check with the inspector on that one. I'm not sure if that varies by jurisdiction.


All times are GMT -5. The time now is 08:20 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved